Specification

Siemens Industry, Inc. SPEEDFAX™ 2017 Product Catalog
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MURRAYSafety Switches
GHN424NW HHN426N HUN361AW
Passed The Test of Time
All Murray safety switches have passed rigid
testing requirements to assure reliable perfor-
mance. In addition to tests designed and
conducted during the development and manu-
facturing processes, switches have performed
successfully in tests witnessed by
Underwriters’ Laboratories. These tests
include those for general purpose safety
switches and those designed for more special-
ized purposes where applicable.
Handle Lock-Off
Heavy duty, “H“ series safety switches have
a provision to lock the handle in the “OFF“
position with a maximum of three padlocks.
Doors may be locked closed with a padlock.
General duty, “G“ series switches may be
locked in the “OFF“ position with one pad-
lock. There is also a padlock feature for lock-
ing the door.
General and Heavy Duty Switches
Feature a Time Proven Design
A fast, long lasting switch design with a clean,
continuous contact. That‘s the switching sys-
tem that gives you on-going reliability. The
concept is simple: split the arc to shorten the
break distance. Uncomplicated mechanics and
common sense design assure reliable perfor-
mance time after time. All switches through
1200A feature visible blade contruction.
Load Break Ratings
All Murray safety switches are UL Listed for
load break applications. Included in this pro-
cess is a series of repeated make and break
tests of the switch contacts while carrying the
full rated nameplate current and rated voltage.
Fuse Interchangeability
General Duty Switches, Prefix G,* will accept
the following UL class fuses:
Class H
Class K
Class R — Requires class “R” fuse kit to
maintain UL listing.
Class J — 100 –200A — field convertible.
Class T — with proper adapter kit (100–600A).
*Except 30 amp plug style switches.
Heavy Duty Switches, Prefix H, will accept the
following UL class fuses:
Class H
Class K
Class R — Requires class “R” fuse kit to
maintain UL listing.
Class J — All 30–200A, 600V and 100–200A,
240V switches — field convertible.
Class L — 800 and 1200A switches only.
Class T — 100–1200A switches with proper
adapter kit.
Gutter Space
“G“ and “H“ series safety switch gutter
dimensions conform to 2008 NEC Article
#312.6(A). Top and bottom gutters conform to
Table #312.6(B).
Horsepower Ratings
Where permitted, all Murray safety switches
are UL horsepower Listed. The switch ratings
are determined by tests that have been per-
formed successfully in the UL overload test
series, including repeated make and break
tests of the stalled motor current of the motor
for which it is being rated.
Some switches have two or more ratings for a
particular voltage and current, and additional
ratings if designed for multi-pole applications.
Depending on the switch and its application,
various ratings may be assigned. All switches
list the ratings on the inside of the cover or
the door. The ampere rating and maximum AC
voltage rating are always shown on the name-
plate on the front of the switch.
Fault Current Performance
Murray Heavy Duty safety switches have suc-
cessfully passed UL high level fault current
tests. This means the risk of mechanical and
thermal damage due to high level short cir-
cuit currents is minimized due to the reliable
switch design.
Suitability tests for service with Class H, R, J,
L, and T fuses have been conducted on heavy
duty safety switches. Representative switch-
es, with test fuses connected in
series with each switch, were subjected to
let-throughs in excess of the capacities of the
largest fuses acceptable by the switches.
To pass the test, the switch must remain
operable after being closed into a high amp
available short circuit current. The test fuse is
sized so that higher levels of let-through cur-
rent and energy will be reached than would
ever occur during normal usage in the field.
Murray General Duty safety switches have
been tested to allow installation on circuits
capable of delivering 100,000 AIC of fault cur-
rent at 240V AC max. with Class R fuses and
also with both Class J and T fuses in
100-200A ratings.
Safety Switches
General Description